1. Field of the Invention
The present invention relates to a magnetic tape reel, a tape cartridge using the same, a recording and reproducing apparatus for recording and reproducing information in the tape cartridge, and an information recording and reproducing method thereof.
2. Description of Related Art
FIG. 18 is a cross-section illustrating the internal structure of a conventional tape cartridge in which a single reel having an upper flange and a lower flange is housed within a case 101 in a rotatable state, whereas FIG. 19 is a plan view illustrating the interior of the tape cartridge shown in FIG. 18. Note that a first container 101b, of which the case 101 shown in FIG. 18 is configured, has been omitted from FIG. 19.
A magnetic tape reel 102 (hereinafter, called a “reel”) is pressed in the upward direction in FIG. 18 by a compression coil spring 128 that acts via a shaft 127. In order to run magnetic tape 103, first, a plurality of engagement gear teeth provided with a reel engaging portion 108 of which a recording and reproducing apparatus is configured are engaged with the plurality of gear teeth provided with the reel. The engagement gear teeth for engaging with a specific gear tooth among the plurality of gear teeth are not stipulated, and the engagement gear teeth that engage with the stated specific gear tooth differ each time the reel engaging portion 108 and the reel 102 engage.
Next, the reel 102 is lifted toward the first container 101a by the reel engaging portion 108. The reel 102 is then rotated at a position slightly distanced from a second container 101b. When the reel 102 is rotated, the magnetic tape 103 is wound upon the reel 102 or let out from the reel 102. As shown in FIG. 19, a metallic lead member 106 is affixed to the end of the tape that is let out. When the tape cartridge is loaded into a a receiving portion of the recording and reproducing apparatus, the lead member 106 is caught by a lead member catching portion of the recording and reproducing apparatus, after which the magnetic tape 103 is pulled out and the lead member 106 is attached to a drive reel. In this manner, the magnetic tape 103 is supplied to a drive system in the recording and reproducing apparatus that includes a guide roller 104 (for example, see JP 2006-085745A).
There are anywhere from several tens to several hundreds of both the plurality of engagement gear teeth in the reel engaging portion, and the plurality of gear teeth provided with the reel corresponding to the engagement gear teeth. It is extremely difficult to form all of the engagement gear teeth and gear teeth with precision. If the shape of each engagement gear tooth and each gear tooth is actually measured, a formation error of several tens of microns to several hundred microns can be confirmed with respect to, for example, the height and angle of the sloped surfaces of the teeth. As a result of the presence of this formation error, when the reel engaging portion and the reel are in an engaged state, the reel tilts in an arbitrary direction, or the position of the reel within the case differs slightly each time it is engaged with the reel engaging portion. This leads to instability in the running position of the magnetic tape, instability in the winding position of the tape upon the reel and so on, which in turn makes it more likely that, for example, the edge of the tape will come into contact with the upper flange or the lower flange. If the edge of the tape comes into contact with a flange, there is the chance that the tape will be damaged, such as the edge of the tape being folded, which increases the likelihood of errors occurring during loading and so on.